Differences in TNF secretion and IL-12 induction between facultative-pathogenic and non-pathogenic mycobacteria infected macrophages. A. BALB/c BMDMs were infected at MOIs of 1:1, 3:1, and 10:1 with M. smegmatis (Msme), M. fortuitum (Mfort), M. kansasii (Mkan), M. bovis BCG, or left untreated (UT). Cells were infected in triplicates for 2 h then washed and incubated in infection media with 100 μg/ml gentamycin for an additional 20 h. Culture supernatants were then collected and the amounts of secreted TNF was determined using ELISA. The values are the mean and standard deviation of triplicate readings and they are representative of three independent experiments. B. The induction of Il-12 gene expression was analyzed by infecting RAW/pIL-12-GFP macrophages with the indicated bacteria for 2 h at an MOI of 10:1. The GFP-expression was analyzed on 5,000 cells 16 h later and the mean and standard deviation of three independent experiments is shown.